Fuel cell apparatus and associated method

Abstract

A fuel cell apparatus is provided that includes an electrochemical energy conversion device comprising an anode and a cathode. The cathode receives an air gas stream flowing thereto. The apparatus further includes a humidity exchange component and a gas scrubber component. The humidity exchange component controls a humidity level in the gas stream flowing toward the cathode. The gas scrubber component includes an active material that reduces a carbon dioxide content level from the air gas stream. A method of using the apparatus is provided.

1 . An apparatus, comprising;
 a housing comprising an electrochemical energy conversion device, the electrochemical energy conversion device having a plurality of electrodes, wherein at least one electrode is configured to receive an air gas stream flowing thereto;   a humidity exchange component capable of controlling a humidity level in the air gas stream flowing toward the electrode; and   a gas scrubber component comprising an active material capable of reducing a carbon dioxide content level from the air gas stream.   
   
   
       2 . The apparatus as defined in  claim 1 , wherein the plurality of electrodes comprises an anode, a cathode, and a third electrode. 
   
   
       3 . The apparatus as defined in  claim 2 , wherein the third electrode functions to locate the generation of oxygen spatially distant from the anode. 
   
   
       4 . The apparatus as defined in  claim 2 , wherein a separator membrane is disposed between the housing and the cathode, wherein the separator membrane allows air to pass into the housing but blocks liquid from flowing out of the housing. 
   
   
       5 . The apparatus as defined in  claim 2 , wherein the anode comprises a hydrogen storage material. 
   
   
       6 . The apparatus as defined in  claim 1 , wherein the housing further comprises a base operable to hold at least one of the plurality of electrodes, a tray disposed proximate to the base, the tray defining one or more spaces for containing the at least one humidity-controlling component, and a cover for the tray that is operable to reduce spillage of the humidity-controlling component from the one or more spaces. 
   
   
       7 . The apparatus as defined in  claim 1 , further comprising a vent configured to allow at least one air gas stream to exfiltrate the housing. 
   
   
       8 . The apparatus as defined in  claim 1 , wherein the humidity-controlling component comprises a saturated aqueous solution. 
   
   
       9 . The apparatus as defined in  claim 1 , wherein the humidity-controlling component comprises one or more solutions selected from the group consisting of: lithium chloride, potassium acetate, magnesium chloride, potassium carbonate, magnesium nitrate, sodium bromide, cobalt chloride, sodium nitrite, strontium chloride, sodium nitrate, sodium chloride, potassium bromide, ammonium sulfate, potassium chloride, strontium nitrate, barium chloride, potassium nitrate, and potassium sulfate. 
   
   
       10 . The apparatus as defined in  claim 8 , wherein the humidity controlling solution is contained within a material selected from the group consisting of a porous particulate substance, a zeolite, a natural clay, and an inorganic gel. 
   
   
       11 . The apparatus as defined in  claim 8 , wherein the humidity controlling solution is contained within a material comprising an organic polymer gel or a porous membrane. 
   
   
       12 . The apparatus as defined in  claim 1 , wherein the humidity-controlling component comprises a metal salt. 
   
   
       13 . The apparatus as defined in  claim 12 , wherein the metal salt comprises an alkali metal halide or a rare earth metal halide. 
   
   
       14 . The apparatus as defined in  claim 12 , wherein the metal salt comprises a metal nitrate, or a metal sulfate, or a metal phosphate. 
   
   
       15 . The apparatus as defined in  claim 1 , wherein the active material comprises an amine functional moiety or an imine functional moiety. 
   
   
       16 . The apparatus as defined in  claim 15 , wherein the active material comprises an amine-functionalized polymer, an amine-functionalized copolymer, or a blend of the amine-functionalized polymer and the amine-functionalized copolymer. 
   
   
       17 . The apparatus as defined in  claim 15 , wherein
 the amine functional moiety comprises one or more of monoethanolamine, diethanolamine, or triethanolamine; or,   the imine functional moiety comprises polyethyleneimine.   
   
   
       18 . The apparatus as defined in  claim 1 , wherein the active material comprises one or more amidine functional moiety. 
   
   
       19 . The apparatus as defined in  claim 1 , wherein the active material comprises an amidine-functionalized polymer, an amidine-functionalized copolymer, or a blend of the amidine-functionalized polymer and the amidine-functionalized copolymer. 
   
   
       20 . The apparatus as defined in  claim 19 , wherein one or both of the amidine-functionalized polymer and the amidine-functionalized copolymer comprises polystyrene, polyacrylate, polymethacrylate, polyimide, polyetherimide, polysulphone, polyarylene oxide, or polycarbonate. 
   
   
       21 . The apparatus as defined in  claim 1 , wherein the active material comprises 1,8-diazabicyclo undec-7-ene, tetrahydro pyrimidine, or N-methyl tetrahydro pyrimidine. 
   
   
       22 . The apparatus as defined in  claim 1 , wherein the active material is supported on a surface of a porous material. 
   
   
       23 . The apparatus as defined in  claim 1 , wherein the gas scrubber comprises a plurality of gas scrubber modules and a crossover valve system,
 wherein a first one of the plurality of gas scrubber modules is capable of reducing a carbon dioxide content level from the air gas stream during a first operation mode, and a second one of the plurality of gas scrubber modules is capable of reducing a carbon dioxide content level from the air gas stream during a second operation mode and   the crossover valve system is capable of responding to controller inputs by switching the air gas stream flow path to flow from the first one of the plurality of gas scrubber modules to the second one of the plurality of gas scrubber modules in response to a change of operating modes to and from the first operation mode and the second operation mode.   
   
   
       24 . The apparatus as defined in  claim 23 , wherein during each operation mode heat from a flow of hot exhaust air coming from the electrochemical cell transfers to the one of the plurality of gas scrubber modules to regenerate the active material. 
   
   
       25 . The apparatus as defined in  claim 23 , further comprising a supplemental heater in thermal communication with the active material that is operable to supplement heat coming from the hot exhaust air flow to regenerate the active material. 
   
   
       26 . The apparatus as defined in  claim 23 , wherein the crossover valve system is further capable of responding to controller inputs by flowing the air gas stream through all of the plurality of gas scrubber modules. 
   
   
       27 . The apparatus as defined in  claim 1 , wherein the air gas stream flows through the humidity exchange component prior to flowing through the gas scrubber component so that there is a transfer of moisture from an outflow of stack exhaust air to the incoming air gas stream. 
   
   
       28 . A method, comprising:
 contacting ambient air to a humidity buffer to control the humidity level of an air gas stream flowing from the ambient air toward at least one of plurality of electrode in an electrochemical cell;   contacting the air gas stream to an active material layer, wherein the ambient air comprises a target gas;   binding the target gas to the active material layer; and   flowing the air gas stream, which is free of the target gas, toward the electrode.   
   
   
       29 . The method as defined in  claim 28 , wherein the target gas is carbon dioxide. 
   
   
       30 . The method as defined in  claim 28 , further comprising maintaining a relative humidity of the air gas stream within the electrochemical cell in a range of from about 70 percent to 85 percent. 
   
   
       31 . The method as defined in  claim 28 , further comprising generating hydrogen, and storing the hydrogen in an anode. 
   
   
       32 . The method as defined in  claim 28 , further comprising contacting the air gas stream to an active material layer in a first gas scrubber module during a first operation mode, and contacting the air gas stream to an active material layer in a second gas scrubber module during a second operation mode, and switching from the first operation mode to the second operation mode. 
   
   
       33 . The method as defined in  claim 32 , further comprising regenerating the active material layer in the first gas scrubber during the second operation mode and regenerating the active material layer in the second gas scrubber during the first operation mode. 
   
   
       34 . The method as defined in  claim 33 , wherein regenerating comprises supplying thermal energy to the active material layers in the first gas scrubber, the second gas scrubber, or both the first and the second gas scrubbers. 
   
   
       35 . The method as defined in  claim 34 , further comprising actuating an electrically powered heater that is in thermal communication with the active material layer, and wherein the thermal regeneration is achieved by the thermal energy supplied by the electrically powered heater. 
   
   
       36 . The method as defined in  claim 35 , further comprising supplying electrical energy from the fuel cell system to the electrically powered heater. 
   
   
       37 . The method as defined in  claim 32 , further comprising switching to a power demand mode and contacting the air gas stream to active material layers in both the first gas scrubber module and the second gas scrubber module simultaneously. 
   
   
       38 . An apparatus, comprising:
 an electrochemical cell comprising an air electrode configured to receive an intake air gas stream;   means for maintaining a defined relative humidity of the intake air gas stream to be in a range of from about 50 percent to about 90 percent; and   means for reducing or eliminating carbon dioxide from the air gas stream.